/Engine/Source/Runtime/UMG/Public/Slate/WidgetRenderer.h
void DrawWindow ( [UTextureRenderTarget2D](API\Runtime\Engine\Engine\UTextureRenderTarget2D) * RenderTarget, [FHittestGrid](API\Runtime\SlateCore\Input\FHittestGrid) & HitTestGrid, [TSharedRef](API\Runtime\Core\Templates\TSharedRef)< [SWindow](API\Runtime\SlateCore\Widgets\SWindow) > Window, float Scale, FVector2D DrawSize, float DeltaTime, bool bDeferRenderTargetUpdate )